Plantwatch: the smelly deception of titan arum’s phallic spadix

It looks like a giant erect penis, stinks to high heaven and warms up to about the temperature of a human body. This is the inflorescence of the titan arum, Amorphophallus titanum, a plant with a phallus-shaped spike called a spadix that stands up to three metres tall, warms up to 36C at night and gives off the stench of a rotting corpse. This wonder is actually a ruse to attract carrion flies and beetles to pollinate the small flowers that are tucked away at the base of the spadix inside a large bucket-shaped leafy wrapper, where the insects are trapped until the flowers are successfully pollinated.

A recent study revealed the plant’s pungent odours were made up of a stinky cocktail of sulphur chemicals, including the aptly named compound putrescine, which is given off by rotting animal carcasses. This foul concoction is released only when the spadix warms up in short pulses.

The titan arum grows in the forests of Sumatra in Indonesia, and to add to its otherworldly qualities, the plant takes years to come into bloom for the first time, and when it does flower, the bloom only lasts a few days.